Characterization of Therapeutic Drug Monitoring Practices of Voriconazole and Posaconazole at a Pediatric Hospital.

OBJECTIVES

To characterize the voriconazole and posaconazole serum trough ordering practices in patients receiving prophylactic and treatment antifungal therapy.

METHODS

A retrospective chart review over a 6-year period of pediatric patients who received voriconazole and/or posaconazole for >24 hours.

RESULTS

A total of 113 patients were included in this study and of these patients, 105 received voriconazole and 16 received posaconazole during the study period. Additionally, 167 trough levels were assessed in this study. Only 50% and 54% of levels were considered within goal recommendations for voriconazole and posaconazole, respectively. The median dose required to achieve goal trough concentration was dependent on drug, indication, and dosage form. Lastly, the most common adverse drug reactions (ADRs) were hepatoxicity, QTc prolongation, and CNS changes, which were in concordance with ADRs documented in the clinical trials for voriconazole and posaconazole. Approximately 20% of patients receiving either voriconazole or posaconazole died during the study period and the median trough in both groups was subtherapeutic.

CONCLUSIONS

Increased monitoring of trough concentrations may be warranted to prevent death or breakthrough invasive fungal infections. Further studies are warranted for assessing the relationship between trough concentrations and treatment outcomes as well as relationship between dosing and achieving goal trough concentrations.